1. Field of the Invention
The present invention relates to anodes of lithium batteries and methods for fabricating the same and, particularly, to a carbon-nanotube-based anode of a lithium battery and a method for fabricating the same.
2. Discussion of Related Art
In recent years, lithium batteries have received a great amount of attention. Lithium batteries are used in various portable devices, such as notebook PCs, mobile phones and digital cameras. Generally, lithium batteries have small weight, high discharge voltage, long cyclic life and high energy density compared with conventional lead storage batteries, nickel-cadmium batteries, nickel-hydrogen batteries, and nickel-zinc batteries.
An anode of a lithium battery should have such properties as high energy density; low open-circuit voltage versus metallic lithium electrode; high capacity retention; good performance in common electrolytes; high density (e.g. >2.0 g/cm3); good stability during charge and discharge processes and low cost. At present, the most widely used anode active material is carbonous/carbonaceous material such as natural graphite, artificial graphite and amorphous-based carbon. Amorphous-based carbon has excellent capacity, but the irreversibility thereof is relatively high. The theoretical maximum capacity of natural graphite is 372 mAh/g, but the lifetime thereof is generally short.
To be used as an anode active material, compared with the carbonous/carbonaceous materials, a metallic material with high capacity is used. For example, the capacity of tin can be above 1000 mAh/g. Thus, in most lithium batteries, a tin film is formed on a current collector to achieve the anode. However, during charge/discharge processes, the size of the anode can increase by as much as 600%. As such, the tin film may be pulverized. As such, the capacity of the lithium battery using tin anode decreases rapidly due to the above-described processes.
What is needed, therefore, is to provide an anode of a lithium battery and a method for fabricating the same, in which the above problems are eliminated or at least alleviated.